The instant invention relates to electrical connectors for connectably transferring power and other electrical signals from a remotely stationed control unit to a plurality of adjustable automotive suspension components, such as electrically adjustable damping-force hydraulic struts and shock absorbers, controlled thereby.
U.S. Pat. No. 4,526,401 to Kakizaki et al. teaches an "Electrical Control System For Adjustable Shock Absorbers" wherein low-voltage, low-current electronic information is exchanged between an electrically adjustable shock absorber and electronic control means therefor that is positioned remotely therefrom and connected thereto via an electrical harness. An electrical connector system is needed between the shock and control means that is firmly attachable to the shock while providing ease of connectibility and serviceability, and while being equally able to withstand the rigors of underhood and wheel well environments, which include exposure to mechanical shock, vibration, impact, and severe moisture conditions.
For example, standards sanctioned by the Society of Automotive Engineers require continuity of operation of such components after exposure to humidity, salt atmosphere, fluid immersion, splash with numerous chemicals and oils, and resistance to dust, sand, and gravel bombardment. Moreover, it is generally accepted that automotive components must operate over a temperature range of -40.degree. C. to 85.degree. C. It will also be noted that automotive suspension components are typically considered zero maintenance items. Standard industry warranties extend for a period of five or more years, or in excess of 50,000 miles, of vehicular use. Thus, electrical connectors for use with such components must be particularly hearty.
Additionally, an electrical connector system for underhood use must be one of low profile design, as space available above a MacPherson strut suspension component is typically restricted by the proximity of the engine compartment hood. Similarly, with regard to a rear shock application, connector system size is limited by the space available within the wheel well. Moreover, while an electrical connector for a strut may be axially mounted upon the upper end of the strut stem, the typical rear shock is secured to the automobile chassis by an axially situated upper mounting loop, thereby requiring a connector system suitable for mounting thereon in a radial direction with respect thereto, i.e., mounted perpendicular to the shock absorber shaft.
The prior art teaches a plug and socket combination for use with electrically adjustable shock absorbers wherein a plurality of cantilevered contact beams projecting axially within the socket mate with recessed contact surfaces on the axially opposed surface of the plug. The flexible circuit leading to the motor within the shock is soldered to the contacts protruding from the opposite end of the socket, whereafter a strain-relief cap is pressed onto, and then glued to the socket and flexible circuit. An O-ring is positioned about the outer stepped surface of the socket, whereafter the socket is press-fit into a bore in the shaft of the shock and glued thereto, thereby compressing the O-ring between the outer surface of the socket and the internal surface of the shaft bore.
The wires leading to the plug are secured to the contacts therein by pressure crimp. An elastomeric cover encompasses the entire plug assembly and extends axially therefrom so as to encompass a portion of the suspension component shaft subsequent to the mating of the plug and socket. A circular snapping arm thereafter secures the plug about the shaft. A second moisture barrier comprising a resilient sealing element is also disposed between the axially opposed, mating surfaces of plug and socket during the mating thereof.
Unfortunately, the connector system taught by the prior art is replete with shortcomings: the connection of the flexible circuit to the jack contacts, the securing of the cap thereto, and the installation of the jack within the shaft bore are painstaking and timeconsuming; consuming; the serviceability of the prior art connector system is greatly impaired due to the use of glue therein; the cantilevered contact beams of the socket are vulnerable to transverse loading during connection and service, whereupon the resultant bending and/or breaking of the contact beams may render the connector system inoperable; arcing and other electrical disruptions between the cantilevered socket contact beams can adversely affect connector reliability and performance, as there are no insulating barriers interposed therebetween; the wires connected to the plug contacts are not provided with any strain relief and, hence, the connections therebetween are susceptible to failure due to mechanical work thereupon; the embrittlement of the glue utilized by the prior art at cold temperatures diminishes the impact resistance of the prior art connector system; and the moisture barriers utilized therein are unable to provide a complete seal, thereby allowing moisture to seep into the suspension component. Additionally, it is to be noted that the prior art has been unable to accommodate suspension components which utilize an axially-disposed mounting loop which fail to provide an axially extending mounting stem for use with the connector system taught by the prior art.